Geologic Investigations in Support of Project Chariot, Phase Iii, in the Vicinity of Cape Thompson, Northwestern Alaska--Preliminary Report

• Main Authors: Kachadoorian, R., Campbell, R. H., Moore, G. W., Scholl, D. W., Lachenbruch, A. H., Greene, G. W., Marshall, B. V., Barnes, D. F., Allen, R. V., Waller, R. M., Slaughter, M. J.
• Other Authors: United States. Department of Energy.
• Format: Report
• Language: English
• Published: Geological Survey (U.S.) 1961
• Subjects: Heat Transfer; Nuclear Explosions; Geology; Freezing; Water; Contamination; Prospecting; Radioactivity; Well Logging; Ground Water; Rocks; Humidity; Motion; Testing; Excavation; Sea; Earth; Temperature; Mineralogy; And Meteorology; Deposits; Mud; Environment; Openings; Cape Seppings; Point Hope; permafrost; Alaska
• Online Access: https://doi.org/10.2172/4065455; https://digital.library.unt.edu/ark:/67531/metadc869294/

BS>Geologic investigations were made at the Chariot test site, at the mouth of Ogotoruk Creek in the vicinity of Cape Thompson, Alaska. IN the area within a 15-mile radius of the site, bedrock consists entirely of consolidated clastic and chemical sediments. The test excavation lies entirely in frozen mudstone which is complexly folded and faulted. Moisture determinations conducted within 10 ft of the surface indicated that the moisture content of the rock ranges from 3.1% in the thawed mudstone to 12.5% in the frozen mudstone. The use of refrigerated diesel fuel as drilling fluid in Holes Charlie and Dog in 1960 overcame the collapse of drill-hole walls owing to thawing of permafrost experienced in drilling by conventional techniques. Work on coastal processes was focused on establishing a physical background for ecological studies being conducted by other investigators and on characterizing the natural movement of sediment as an aid in evaluating the success and safety of the proposed nuclear test. Piston-core samples from lagoons which do not contain the mouths of rivers and streams showed that only about 10 cm of sediment were laid down in the lagoons since the last major rise of sea level. The shoreline history of the area was inferred from these samples. The two new holes were used to provide temperature information needed for a quantitative evaluation of the thermal regime ot lower Ogotoruk Creek Valley. The thermal regime of permafrost was found to not be in equilibrium with the present position of the shoreline or the present climate. Preliminary calculations indicated that the flow of heat to the surface from the earth's interior is on the order of one-millionth of a calorie per square centimeter of surface per second. A series of gravity measurements between Kotzebue and Point Hope indicated a broad uneven gravity low with double minimums near Cape Seppings and Kivalina. The possibility of radioactive contamination of shallow and deep aquifers existing in the area was investigated. (M.C.G.)